A backup-power automatic switching device for power grid may automatically provide backup-power to electrical equipment or switch power source of the equipment to the backup-power when the main power source fails due to certain reasons. The backup-power automatic switching device is an automatic safety device that enhances reliability of power supply, and may be abbreviated as BAS. The backup-power automatic switching device is an important equipment in power operation to enhance reliability and continuity of power supply. Nowadays, BAS devices have been widely used. The BAS device is required to be inspected before new installation which puts the device into operation, and is required to be tested and calibrated periodically during operation.
Existing calibration technologies may include simulating circuit parameters such as voltages and currents in actual lines, providing switch input and receiving switch output by simulation circuit breakers, and sampling action time of the BAS device using devices such as time measurement apparatus. These methods have complex wiring during specific work process, cannot simulate some required test items of BAS devices. Further, these methods are not able to accurately simulate some complicated failure sequences. For example, Chinese granted patent publication No. CN 201178332Y, entitled “a debugging device for backup-power automatic switches”, discloses a debugging device for BAS including a debugging interface and a debugging circuit. The debugging circuit may accept instructions from the interface and output a debugging status using two dual-position relays with magnetic latches. The debugging device is overly simple and may not accomplish multiple test items required by current BAS devices.
Besides, Chinese granted patent publication No. CN 101504449, entitled “a testing apparatus for backup-power automatic switching devices”, discloses a testing apparatus for BAS devices with high level of integration. Despite considerable progress, due to limited conditions, the testing apparatus cannot simulate various scenarios that may potentially occur in reality, especially some unusual circumstances, such as breaker tripping or breaker refusing to action, main transformer failure, manual closing, intertrip, etc. In addition, although the testing apparatus is claimed to have simple wiring, its specific wiring connection device is not disclosed. The testing device cannot simultaneously display usage status, either.